MOSCOW (AP) — An explosion apparently caused by natural gas has heavily damaged a nine-story apartment building in southern Russia, leaving two people dead and 12 injured.

Rescue workers were searching through the rubble, and officials said at least 11 residents of the building are unaccounted for.

The explosion occurred Monday in Astrakhan, a city 800 miles (1,300 kilometers) southeast of Moscow.
A spokesman for the regional emergencies ministry, Oleg Grekov, told the ITAR-Tass news agency two bodies were pulled from the rubble late Monday.

Regional Investigative Committee spokeswoman Anna Konyaeva said the blast first blew out a lower section of the building. As people rushed to help, the upper six stories collapsed.

Explosions of gas canisters in Russian homes and businesses are common.